
Glass. 



Book 'A 



Studks in Infantile Paralysis 



During 1910 



BY THE 



masbindtoti State Board of liealtb 



E. L. BOARDMAN, PUBLIC Peintbr, Oltmpia. 



/ 

REPORTT L 



OF 



INFANTILE PARALYSIS 



IN THE 



STATE OF WASHINGTON 
DURING 1910 



BY 



EUGENE R. KELLEY, M. D., 

Assistant State Health Commissioner 

WALTER GELLHORN, M. D., 
JOHN B. MANNING, M. D. 



WITH AN 
APPENDIX 

INFANTILE PARALYSIS IN THE CITY OF SEATTLE 

BY 

WILLIS H. HALL, M. D., First Assistant Medical Inspector, 
SEATTLE HEALTH DEPARTMENT 



OLYMPIA, WASH.: 

E. L. BOARDMAN, PUBLIC PRINTER 

1911 






LETTER OF TRANSMITTAL. 



Seattle, Wash., September 1, 1911. 
Dr. Elmer E. Heg, 

State Commissioner of Health, Seattle, Wash. 

Dear Doctor : I have the honor to submit the completed 
manuscript of the report on the prevalence of infantile paralysis 
in this State during the season of 1910. 

This report has been a work of considerable scope and un- 
foreseen obstacles have delayed its completion for many months 
beyond the original plans. While it contains no startling new 
facts or theories, when compared to similar investigations, yet 
owing to the peculiarities of climate and physical geography 
in this State, it is perhaps safe to say that it adds some data, 
though largely of a negative nature to the subject of the pos- 
sible inter-relationship between climate, season, rainfall and 
infantile paralysis. 

I wish to take advantage of this opportunity to express my 
thanks to my colleagues in this report. Doctors Walter Gell- 
horn and John B. Manning, both of whom have given unspar- 
ingly of their time for the purpose of carrying on this work to 
a successful completion, not infrequently at a personal sacri- 
fice and with no financial remuneration. 

I also wish to thank the medical profession generally and the 
health officers of the State in particular, for the enthusiastic 
cooperation they have displayed during this investigation. 
Respectfully submitted, 

Eugene R. Kelley, 
Assistant Commissioner. 



1:n 



REPORT OF INFANTILE PARALYSIS IN THE STATE 
OF WASHINGTON FOR THE YEAR 1910. 



INTRODUCTION. 

The disease infantile paralysis has increased with remark- 
able suddenness in the United States in the last four or five 
years. Previous to 1910, infantile paralysis was not a re- 
portable disease in the State of Washington and, hence, there 
are no morbidity records prior to the year just mentioned, but 
the mortality records show that the disease was either so rarely 
fatal or so universally overlooked as a cause of death that it 
scarcely appears on the mortality returns for this State from 
the time of the adoption of the present vital statistics law in 
1907 until midsummer of 1910. Therefore, it would appear 
that the disease was comparatively infrequent or, at any rate, 
much milder than was the case in the year 1910. 

At the conference of the State and Provincial Boards of 
Health of North America, held in Washington, D. C, in June, 
1909, the president of the conference took this disease as a 
subject of his address, and gave an account of a localized but 
severe epidemic which occurred in his state — Wisconsin — the 
previous autumn. In the discussion that followed the repre- 
sentatives of the Pacific Coast states unanimously agreed that 
the disease had not been prevalent up to that time to any marked 
degree on the Coast, and the prediction was made that the Pacific 
Coast would probably be visited by this disease within the next 
two years. On these grounds, the Washington State Board of 
Health made infantile paralysis or anterior poliomyelitis a re- 
portable disease at the annual meeting of the Board in Janu- 
ary, 1910. This provision proved to be wise, since early in the 
summer of 1910 cases began to be reported. 



Washington State Board of Health 



As soon as it was evident that the disease was appearing in 
an unusual degree in various parts of the State, special blanks 
were prepared by the State Health officials and mailed to every 
physician whose address was on file at the State Board of Health 
office. The response by physicians was immediate, and the in- 
terest taken was marked, and, as a result, careful and compara- 
tively complete blanks began to be collected. 

When it was evident that the number of cases would be so 
great as to justify such a step, a special investigation was de- 
cided upon, and two of the authors of this report, Drs. Gellhorn 
and Manning, volunteered to make such an investigation. These 
two physicians visited all the more accessible communities where 
any considerable number of cases had been reported, and ex- 
amined each available case. In many instances this could not 
be done until months after the onset of the disease, but on the 
whole this delay has probably only added to the value of the in- 
vestigation, since it gave a valuable clue to the extent of the 
paralysis after the acute stage had subsided. Nearly half of 
the cases that had previously been reported by physicians were 
subsequently visited by the investigators. 

The purpose of this investigation was both for confirming 
the diagnosis and obtaining more data on surroundings and 
conditions, which might have had some bearing on the disease. 

Just as the compilation and analysis of the facts thus ob- 
tained was commenced, the officers of the Washington State 
Board of Health were so fortunate as to receive a call from 
Dr. Mark W. Richardson, Secretary of the Massachusetts 
State Board of Health, which has probably done the most epi- 
demiological investigation on this disease of any public health 
organization in the United States. At his suggestion, it was 
decided to follow very closely the lines laid down and con- 
sistently followed by the reports of the Massachusetts Board 
since their first report in 1908, as it was felt that putting the 
report in this form would add greatly to its value for purposes 
of comparison. 



Studies in Infantile Paralysis 



SECTION I.— GENERAL CONDITIONS. 

HISTORY. 

Increase. 

Perhaps the most striking feature of infantile parah'sis in 
the last ten years has been its enormous increase in frequency 
throughout the civilized world, more especially in the north tem- 
perate zone. 

Since the recent widespread interest in this disease has 
aroused so much discussion, observers have not been wanting 
who have somewhat challenged the assertion that the disease 
was prevalent to an extent never before known. It is possible 
that there have been serious epidemics of infantile paralysis for 
centuries. If such occurred they were not sufficiently extensive 
nor sharply enough localized in time or place to impress ob- 
servers of previous generations with the probable infectiousness 
of the disease, for it is only in recent years, comparatively 
speaking, that recognition of distinct outbreaks of infantile 
paralysis has occurred. 

For the past twenty-five or thirty years outbreaks have oc- 
curred in various parts of Europe with rather steady tendency 
to increase in frequency and severity. It has only been in the 
past six or seven years that the disease has obtained a firm foot- 
hold in the United States in its epidemic form. Just why this 
disease which has been, at least in some of its forms, well recog- 
nized for generations, should of late years assume a tendency to 
spread to a degree never before noted, is one of the mysteries of 
epidemiology which probably will never be satisfactorily an- 
swered. Man}' ingenious theories to account for this unmis- 
takable tendency have been brought forth and well argued by 
careful observers who have studied the outbreaks in the United 
States and abroad in the last five or six years. None of these 
theories give a very satisfactory answer to this epidemiological 
mystery, and some of them would appear to be contradictory. 



6 Washington State Board of Health 

Scandinavian Influence. 

In point of time the great modern outbreaks of infantile 
paralysis seem to have originated in the Scandinavian Penin- 
sula, where large and carefully studied epidemics have occurred 
in several localities since the year 1899, when Medin, the Scandi- 
navian observer, made a very careful study of the disease in its 
acute stage. Later Scandinavian observers increased our knowl- 
edge of this mysterious malady, particularly Harbitz and 
Scheele, who greatly extended the pathological conception of 
the disease, and Wickman who practically revolutionized pre- 
vious conceptions of the disease by demonstrating that several 
morbid states, which had hitherto been considered as entirely dis- 
tinct, were, in all probability, merely manifestations of the same 
infection acting upon different parts of the nervous system. 
Upon this brilliant conclusion he readjusted entirely the classi- 
fication of infantile paralysis, dividing it into no less than eight 
distinct types. This classification has been of inestimable 
value to all subsequent observers, and all later observations upon 
the nature and character of infantile paralysis have only tended 
to establish on a firmer basis the general soundness and good 
logic of Wickman's classification. 

Infantile Parcdysis in United States. 

Infantile paralysis had been extremely rare in an epidemic 
form in the United States until the last decade. There had been 
a few isolated small epidemics, notably one in Vermont in 1894 
in which there were 126 cases. 

The year 1907 is a very important date in the history of in- 
fantile paralysis, since in that year both Massachusetts and 
New York city reported severe outbreaks. The one in New 
York city and near vicinity is the largest on record, there be- 
ing nearly 2,500 cases reported. In Massachusetts 234 cases 
were reported. In New York city all the requirements of an 
epidemic, in its strictest sense, were fulfilled. In only one center 
in Massachusetts were the total number of reported cases suf- 
ficiently large to be classed as an epidemic. 



Studies in Infantile Paralysis 



From these Eastern states the disease has steadily worked 
westward. In the summer of 1908 outbreaks were reported in 
Minnesota, Wisconsin and Iowa, while the following summer 
found the disease unusualty prevalent in practically all the 
states previously noted, and in addition fresh outbreaks in Ne- 
braska, Illinois and Kansas. In the autumn of 1909 infantile 
paralysis for the first time was reported in an epidemic form on 
the Pacific Coast — in Oregon. Practically all these cases were 
confined to the valley of the Willamette river ; in other words, 
in or near the city of Portland. In the summer of 1910 the 
-disease was reported as unusually prevalent in a great many of 
the Eastern states, in all the Middle Western states, in which it 
had been reported in previous years, with the exception of 
Michigan and Illinois, where relatively few cases were reported. 
A considerable number were reported from the province of On- 
tario. Nearly all the Southern states, with the exception of 
Yirginia and South Carolina, reported that cases were compar- 
atively few. In the extreme Northwest there was a marked in- 
crease — 112 cases being reported from Oregon, 397 from Wash- 
ington, 96 from Idaho, 170 from Montana, 75 from British 
Columbia, and 11 from the province of Alberta. By merely 
glancing at the increased number of reports of outbreaks of in- 
fantile paralysis for the past four years, it can be noted that a 
definite tendency for the disease to spread slowly westward has 
been consistently maintained. It is curious that, as a rule, the 
disease has been much more prevalent in the northern half of 
the United States. Utah and Cahfornia alone of the South- 
western group of states reported any particular prevalence. 
The fact that practically all the state in which infantile paral- 
ysis is at present a reportable disease have only made it re- 
portable within the last three years, may explain, to a certain 
degree, the very great increase in the number of reported cases. 
In this connection, Bradford and Lovett* state that in their 
opinion "the conclusion that anterior pohomyelitis is becoming 
much more frequent, must be accepted with caution, because of 



♦Boston Medical and Surgical Journal, June, 1910. 



8 Washington State Board of Health 

the fact that it has been more frequently called to the attention 
of the profession and more freely recognized than formerly." 
Making allowance for this factor, which the study of literature 
seemed to justify, their conclusions are that epidemics of in- 
fantile paralysis have, undoubtedly, greatly increased in the past 
few years in various parts of the world, to such an extent that 
it cannot be explained as merely due to increased interest and 
study of the disease, and also that the northern part of the 
United States has suffered more than any other part of the 
world. Richardson gives the following interesting statistics on 
this same point. He states that there are only about 300 cases 
on record of epidemic infantile paralysis in the United States 
up to 1905. That in the five years, 1905-1909 inclusive, there 
were in all 5,400 cases reported, and in the single year of 1910, 
no less than 9,000 cases. 

Increase in Washington. 

Observation in this State may throw some light upon this 
point. In common with most other sections, infantile paralysis 
had been not infrequent in its sporadic form for many years, 
and several physicians, notably in the eastern part of the State, 
when they reported their 1910 cases, gave a history of a ten- 
dency for the disease to occur in an epidemic, or sub-epidemic, 
form in their vicinity for several years. Yet, from a number of 
physicians came the unsolicited remarks upon the history sheets 
and accompanying correspondence that the disease had increased 
sharply during the summer, of 1910 to a degree and extent which 
they had never before seen. Moreover, the majority of physi- 
cians appear to have reported their 1909 cases almost as care- 
fully as their 1910 cases, as no limitation to the year 1910 only 
was indicated upon the circulars which were sent out to the 
profession when reports of cases were first solicited. It ap- 
pears from the comparatively few cases which were reported as 
having occurred in 1909, that the disease had increased aston- 
ishingly in the following year, to such an extent that it can 
properly be designated as having passed in a single season fromi 



Studies in Infantile Paralysis 9 

a comparatively infrequent sporadic disease to a formidable 
epidemic disease. 

INFECTIOUSNESS OF THE DISEASE. 

HilVs Statistics. 

At present infantile paralysis is held by competent observers 
to be infectious in character, although it is to be carefully noted 
that the disease is not very "contagious," as that term is com- 
monly used. Many observations by epidemiologists are now re- 
corded which in themselves are practically sufficient to demon- 
strate its communicability, but the conclusions of Wickman 
that the disease is not very transmissible, have been borne out 
by practically all subsequent observers. This point is well il- 
lustrated by Hill of Minnesota, who showed thatfEhe percentage 
of secondary cases in the same family, in a series studied by 
him, was only 17%. Contrasting this with the records of other 
communicable diseases, he presented the following table as to 
relative infectiousness : 

Scarlet fever percentage, secondary cases 40% 

Typhoid fever percentage, secondary cases, about. 30% 

Diphtheria percentage, secondary cases 29% 

Infantile paralysis percentage, secondary cases. . . 17% 

He further compared the percentage of cases of scarlet 
fever, diphtheria and infantile paralysis, following exposure to 
known cases, although not in the same family, and in this list 
found only 6% of infantile paralysis cases in which there was a 
history of exposure to infantile parlysis ; while with diphtheria 
and scarlet fever the percentages of exposure were 17% and / 
22% respecively. This rather peculiar feature of infantile 
paralysis, namely, that the disease will frequently fail to develop 
under conditions where from our knowledge of infectious dis- 
eases in general it would be expected that the largest number 
of secondary cases would develop, has always been one of the 
most baffling features of this disease. 

Laboratory Results. 

This relative low grade of contagiousness might have long 
left the exact status of its infectiousness more or less in doubt 



10 Washington State Board of Health 

had it not been for the brilhant laboratory work of Flexner and 
Lewis, of the Rockefeller Institute, who in November, 1909, 
demonstrated that by inoculating monkeys with emulsions of 
the spinal cords from children who had died with infantile pa- 
ralysis, that the disease was unquestionably infectious, because 
they could thereby produce a disease practically identical in the 
monkeys. At first inoculations were made directly intradurally, 
but subsequent experiments rapidly proved that the disease could 
be produced with almost mathematical exactness whether the 
inoculations were made intradurally, intraperitoneally, or sub- 
cutaneously, or even by introducing the virus into either the 
naso-pharyngeal or gastro-intestinal tracts — sometimes without 
even wounding the mucous membrane. These last two points 
practically demonstrate that, in all probability, the routes of in- 
fection are either through the respiratory or digestive tracts. 
An immense amount of work has since been done by investigators 
throughout the world in the endeavor to isolate some organism 
from the nose or gastro-intestinal tract which would reproduce 
the disease experimentally, but up to the present time all such 
attempts have failed. 

Flexner and Lewis, carrying their experiments further, dem- 
onstrated that the virus from an inoculated monkey could be 
carried through a large number of secondary inoculations, 
which conclusively proved that the disease was due to a living 
organism, and thereby established its infectious nature beyond 
all question, but, at the same time, they discovered that the 
virus could not be obtained by bacterial filters, which led them 
to the conclusion that infantile paralysis is probably due to an 
ultra microscopic organism of an unknown nature, similar to 
that producing rabies or yellow fevor. This great discovery 
by Flexner and Lewis is, up to the present time, the most im- 
portant addition that has been made to our knowledge of in- 
fantile paralysis. 



Studies in Infantile Paralysis 11 

COMMUNICABILITY. 

Wickman, from his studies In the Scandinavian Peninsular, on 
epidemiological grounds was led to conclude that practically 
every case has had contact with another case either (a) direct, 
(b) through another healthy person, or (c) by means of a 
house, and believed that the disease was frequently carried by 
apparently healthy persons. This conclusion has been con- 
stantly confirmed by all subsequent epidemiological work. The 
conclusion is practically inevitable In conjunction with the la- 
boratory work that the spread of the disease can only be ex- 
plained through carriers, either human or otherwise, who do 
not exhibit any symptoms themselves but, nevertheless, transmit 
it to others. 

The manner In which infantile paralysis appears in remote 
and apparently inaccessible districts, is a puzzling feature of 
the disease, but when the manifold ways in which the entire civ- 
ilized world today Is kept in communication are once recalled. It 
is not inconceivable, nor at all improbable, that healthy car- 
riers may explain even the most Isolated outbreaks. 

Richardson points out that all means of travel, especially by 
electric railways and automobiles, have multiplied enormously 
in the last decade, and believes that this fact may have an Im- 
portant bearing upon the tremendous increase of the disease 
during the same period, while, at the same time. It complicates 
enormously the problem of tracing infection. 

Question of Importation. 

Assuming that the disease was introduced into this country 
in the epidemic form, from immigrants who brought it from the 
scene of the great Scandinavian outbreak of the five years pre- 
vious to 1905, it has been noted by some observers that an un- 
usually large proportion of cases reported are either among 
families of recent Scandinavian immigrants or Scandinavian 
descent. It has been argued, and with certainly a great de- 
gree of plausibility, that one of the probable reasons why the 
state of Minnesota has suffered so severely from infantile pa- 



12 Washington State Board of Health 

raljsis, has been on account of the tremendously large immigra- 
tion of Scandinavians into that state. Yet the disease in the 
West generally does not seem to conform very closely to the 
distribution of Scandinavian immigrants. In the State of 
Washington there were one or two localized sub-epidemics, 
where the occurrence of the cases was predominantl}- among 
Scandinavian children. But when allowance is made for the 
fact that a large percentage of the population of this State is 
Scandinavian, it would not appear that the disease was unduly 
prevalent among the people of that race. 

Other Factors of Transmissihility than Personal Contact. 

A large number of possible methods of transmission of the 
disease have been suggested and, to some extent, investigated. 
Thus, Lovett and Richardson, in their recent work, have drawn 
attention to several of these factors, the most notable ones being 
dust and animal paralysis. It has usually been noticed that 
the disease is more prevalent during the dusty season. 

Flexner has proven experimentally that flies and possibly 
other insects may retain the virus on their feet for at least 48 
hours and, therefore, it is not possible at the present time to 
definitely exclude insect carriers as a possible means of trans- 
mitting infantile paralysis. 

Animal Paralysis. 

Paralysis among various domestic animals has been reported 
coincident with or just preceding epidemics of infantile pa- 
ralysis among human beings. While the greater number of 
these reports are probably apocryphal, which has certainly been 
the case in this State, yet there appears to be a certain residue 
of fact in this connection which is at least suggestive and 
worthy of investigation by skilled veterinarians in conjunction 
with epidemiologists and laboratory workers. It is reported 
that a research into the question of possible animal transmis- 
sion is already being inaugurated by Dr. Theobald Smith, of the 
Harvard Medical School, and the results from a thorough and 
extensive investigation into animal paralysis, both in the field 



Studies in Infantile Paralysis 13 

and in the laboratory, ought certainly to throw valuable light 
upon this phase of the subject. 

AGE. 

Practically all investigators are unanimous in their opinion 
that the disease is most frequent between the ages of two and 
three 3'ears, and such is the experience in this State. How- 
ever, neither age nor sex is spared, and it would appear that, 
as a general rule, the disease is moi'e severe in its manifestations 
in adults than children. 

QUARANTINE. 

Present Quarantine Procedure. 

In accordance with the recommendations in 1910 of the 
American Pediatric Society and the Conference of State and 
Provincial Boards of Health of North America, the State Com- 
missioner of Health instituted a modified quarantine for a period 
of three weeks from the acute onset of the disease. The term 
"modified quarantine" being explained in the quarantine notice 
to mean that no children be allowed to enter or leave the prem- 
ises, and that no adults whose occupations would habitually place 
them in contact with assemblages of children, should remain on 
the premises and continue their usual occupations, and empow- 
ering health officers to institute a rigid quarantine in case the 
privileges extended to adults be abused.' In other words, this 
is a quarantine very similar to that maintained for measles in 
the State at the present time. 

Theory of Quarantine. 

It is ver}^ questionable just how much value there may be in 
quarantine measures in connection with infantile paralysis. As 
has been aptly observed, the practice of quarantine is more or 
less of a confession of epidemiological ignorance in many dis- 
eases, since it is based upon an empirical belief, founded upon 
observations of centuries, that certain diseases spread readily 
from one person to others. At the same time it is often a con- 



14 Washington State Board of Health 

fession of ignorance as to just how the disease spreads, or how 
it can be scientifically prevented, and, therefore, in lieu of this 
exact knowledge it is considered safest for the purpose of the 
greatest good to the greatest number, that whatever individuals 
happen to be afflicted with such diseases and also those who 
come in immediate contact with them, should be kept strictly 
isolated from other people. On these grounds it appears wise 
that in cases of infantile paralysis patients at the onset of the 
disease should be isolated, and members of their family ex- 
cluded from schools and public assemblages, particularl}" where 
they would of necessity come in close contact with children. 

Possible Fallacy of Quarantine in Infantile Paralysis. 

Observations upon the nature of human carriers as a means 
of transmission in many infectious diseases has thrown all our 
older conceptions as to the effectiveness of a general quarantine 
into great confusion ; and the experimental reports of Osgood 
and Lucas* have thrown still greater doubt upon the effective- 
ness of any short quarantine in infantile paralysis. They dem- 
onstrate that the nasal-mucous membrane of two monkeys simul- 
taneously inoculated with poliomyelitis, remained infectious for 
extremely diverse periods of time, being only six weeks in one 
case and no less than five and a half months in the other. It is 
very important that much confirmatory work be done along this 
line since there seems to be sufficient analogy between the dis- 
ease in man and the anthropoid apes to justify considerable 
weight being given to the results of such experiments, although 
we cannot as yet take experimental results from monkeys and 
apply them in toto to the disease in human beings. For ex- 
ample, if such experiments should be carried out in a large series 
of monkeys and it was found that in five-sixth or seven-eighths 
of monkeys observed that the nasal mucous membrane retained 
its infectiousness for only six weeks or less, it would greatly 
strengthen the stand that has been taken by the American Or- 
thopedic Association, the American Pediatric Society and the 

Journal A. M. A., February 18, 1911. 



Studies in Infantile Paralysis 15 

Conference of State and Provincial Boards of Health. In 
fact it would raise the question at once as to whether an abso- 
lutely strict quarantine for six weeks were not advisable. If, 
on the other hand, it was found that the nasal mucous mem- 
branes in but few monkeys cease to he infectious in a month or 
six weeks, or if a great majority of them maintained this power 
for diverse hut protracted periods of time, an important ex- 
perimental point would he therehy estahUshed which, when 
coupled with clinical investigations, might justify municipal 
and state health authorities in the ahandonment of all isola- 
tion or quarantine in infantile paralysis as imposing an un- 
necessary hardship without providing adequate compensatory 
benefits to the puhlic. However, in the present stage of our 
knowledge upon the subject, it would appear that the modified 
quarantine is a most wise precaution, and the officers of this 
Board arc in favor of the resolutions adopted during the present 
year by the American Pediatric Society and the National Con- 
ference of State and Provincial Boards of Health, which bodies 
recommended placarding and a fairly thorough isolation of the 
patient, particularly from children, for a period of at least four 
weeks. 

TWO-YEAR PERIODICITY. 

It has been pointed out by several observers that this disease 
seems to exhibit a tendency to recur with greater severity in al- 
ternating seasons. The Massachusetts observers have noted a 
distinct tendency for the disease to occur with greater intensity 
in alternating years for the past five years, and in addition they 
have particularly noted that in special localities there was al- 
most invariably a comparatively complete immunity from the 
disease during the 3^ear following a season of unusual severity. 
It is too early to determine whether there is any such tendency 
in this state, but it is very noticeable that after the unusual oc- 
currence of the disease in the past season, and with all the in- 
terest that is still manifested in it by the profession, that very 
few cases have been reported thus far in the State during the 
present season — only twenty cases being reported to the State 
Board up to August 1st. 



16 Washmgton State Board of Health 



PROPHYLAXIS. 

Aside from the protection which quarantine may give, there 
are very few definite points that have been ehcited of positive or 
even probable value in the prevention of infantile paralysis, in 
spite of the tremendous amount of research and clinical ob- 
servation that has been directed upon this disease. 

Sprinkling. 

On the ground that the virus was transmitted in dust, it has 
been frequently recommended that streets and private premises 
be carefull sprinkled during an epidemic, but the value of such 
a procedure is exceedingly doubtful. 

General Precautions. 

In a general way, it is safe to advise that children be kept 
away from public gatherings and prohibited from using the 
common drinking cup in the face of an epidemic, although when 
it is noted how frequentl}^ cases occur under apparently most 
isolated conditions, while, at the same time, much more populous 
communities in the same section escape entirely, grave doubts 
are at once raised as to the effectiveness of even these obvious 
precautions. 

Fumigation and Disinfection. 

It is certainly advisable that as soon as possible after the re- 
covery of the patient the house be fumigated, if only on the 
grounds that it can do no harm and may possibly destroy any 
residual virus. 

It is, of course, very important that, as in cases of diphtheria 
or typhoid fever, all the discharges, including in this term 
sputum, feces and urine, and all the articles such as towels, linen 
and eating and drinking utensils, that have been in direct con- 
tact with the patient, should be thoroughly disinfected, pre- 
ferably by boiling, before or immediately upon leaving the sick 
room. It also goes without saying that the hands and clothing 
of physicians, nurses and attendants upon the sick patient should 



Studies in Infantile Paralysis 17 



be handled with the same precautions as in other directly in- 
fectious diseases. 

Diet and Exercise. 

It is also a wise general precaution, even though clinical ob- 
servations fail to corroborate previous ideas in this direction, to 
recommend careful attention to children's diet in order to pre- 
vent gastro-intestinal disorders, and to recommend that care be 
taken to prevent undue exposure to dampness or over exertion. 

Urotropin and Peroxide of Hydrogen. 

Two laboratory discoveries have added ver^- materially to the 
methods of prevention. Both of these have been made in the 
laboratories of the Rockefeller Institute hj Flexner and his as- 
sociates, Lewis and Clark. 

The first discovery was that of Flexner and Lewis, who found 
that a 1% peroxide of hydrogen solution would rapidly kill the 
virus of infantile paralysis. They also discovered that by im- 
mediately spraying the nasal passages of monkeys after inoc- 
ulating them with the virus, that the disease could be practcally 
uniformly prevented. Since a solution of this strength, as far 
as known, is entirely harmless, unless used excessivel}- frequent, 
it would appear to be wise on the part of physicians to carry 
out as a routine procedure the use of a gargle or mouth and 
nasal spray or swab directly applied to the mucous membrane of 
a 1% solution of peroxide of hydrogen, both upon the patient 
in the earh' stages, and even more particularh^ upon those who 
have been closely exposed. It w^ould also be a wise precaution 
for health officials to advise the public generally to use such a 
precaution in the face of an epidemic. As the ordinary commer- 
cial preparation of hydrogen peroxide contains about 39r of 
the peroxide, the making of a 1% solution is a matter of such 
simplicity that it can easily be entrusted in the hands of any 
intelligent person. 

Flexner and Clarke quite recently have demonstrated, from 
the experimental standpoint, that the use of a drug which has 
been reconmiended for several years by msmy health officials 
—2 



18 Washington State Board of Health 

purely on empirical grounds — urotropin — has a very sound sci- 
entific basis. They demonstrated that while not universally 
successful,' a considerable proportion of monkeys may be pro- 
tected against subsequent intra cerebral Inoculations of the 
virus, if they are fed on urotropin. It had been previously dem- 
onstrated that when urotropin was administered it was excreted 
into the cerebro spinal fluid as well as Into the urine and, without 
doubt, this is the reason for Its germicidal action when used in 
connection with the virus of Infantile paralysis ; but It may be 
readily seen that In order to obtain any efficient protection by 
the use of this drug, It Is necessary that it be begun for some 
time previous to the inoculations and continued constantly up 
until the time of Inoculation. 

Applying these observations to the case of human beings. It 
would appear that the use of urotropin is of real service as a 
proplwlactic, but all observers are practically agreed that It is 
of little or no value after the infection is once established. Sev- 
eral physicians in this State have reported that they have reg- 
ularly used both the peroxide of hydrogen gargle and urotropin 
in liberal doses In their own children during the present season, 
simply as a prophylactic measure In possible outbreak of in- 
fantile paralysis In their community, and this would seem to be 
a most wise procedure. 

PATHOLOGY. 

The knowledge gained by utilizing the vast and varied ma- 
terial gathered during the recent epidemics, has proven that a 
great many cases, formerly considered as cryptoa;cnetIc or of 
different etiology, belong to the same disease, hitherto called 
anterior poliomyelitis or infantile paralysis. Furthermore, this 
disease has shown such an extensive variation In pathologic lo- 
calization and the age of the affected patients, that the name 
under which It was traveling did not adequately describe the 
disease. A disease attacking equally a baby of four weeks or a 
man of sixty years, cannot very well be called infantile. As the 
estabhshed facts prove that the disease is neither confined to 



Studies in Infantile Paralysis 19 



the cord, nor to the anterior horns, nor to the gray matter 
-above, but that brain, meninges, posterior horns, and grey and 
white matter are alike affected, the fallacy of the name anterior 
poliomj'elitis, or an inflammation of the anterior gray matter of 
the cord, becomes at once obvious. Until a better name is found 
it may seem advisable to follow the example of many investiga- 
tors in accepting the name Heine-Medin's disease, thus honor- 
ing both the men who first respectively described this disease and 
recognized its great variety. 

In this report, serving only practical purposes, it is only 
necessary to mention that the pathological changes start in the 
blood vessels which appear engorged and dilated, both arteries 
and veins alike. The histological changes represent a round 
cell infiltration of the adventitia, which attacks likew^ise the in- 
testinal tissues and secondarily the ganglion cells. The abund- 
ance of blood vessels in the anterior horns explains the predi- 
liction of the disease to settle here, but a special affinity of the 
virus for these ganglion cells may be possible. The affection of 
the cord is always accompanied by an inflammatory process in 
the pia mater. As the infiltration found in the fibers of the pos- 
terior roots, the arachnoidea and the spinal ganglia themselves 
will easily account for the various irritative symptoms, the stiff 
neck and pain on moving. A marked and extensive inflamma- 
tory oedema is always present and will cause paralytic symp- 
toms which disappear with the oedema, 

Restitution of completely destroyed ganglion cells does not 
take place but the less affected cells may overcome the effect of 
the virus and regain their original function. Complete de- 
struction is followed by byghcus scar formation. 

In our State the result of only one post mortem is known. The 
boy died with symptoms of the Medullary type, yet the his- 
tological examination of the cervical cord showed the typical 
pathological changes, although the symptoms were purely me- 
dullary. 



20 Washington State Board of Health 

PROGNOSIS. 

The impossibility in each instance of giving anything ap- 
proaching an accurate prognosis during the acute stage of the 
extent of the residual paralysis is a well known fact. There are 
no means of determining at the onset to what extent the paral- 
ysis will improve. It is probably true that a too depressing 
prognosis is usually offered to the parents. This gloomy out- 
look is the result of an expectation of obtaining a complete re- 
covery. With such an end in view it must be admitted that the 
prognosis is bad. The prognosis for a fair recovery, i. e. con- 
sistent with walking without crutches, with or without braces, 
is good. As regards life, the recent outbreaks show an average 
immediate mortality of about 10%. This was the experience 
also in this State. The ultimate prognosis as regards life in 
the 90% that survive the acute state is excellent. It must be 
constantly borne in mind that there is on the part of nature a 
tendency present in each case towards spontaneous recovery. 
This encouraging feature may be active months and even years 
after the onset. The mentality is in no wise impaired, with some 
possible exceptions in the cerebral types. 

SYMPTOMATOLOGY. 

Vagueness of Early Symptoms. 

The observations during the outbreak in the State of Wash- 
ington confirm the experience gained during other epidemics 
that the symptomatology of epidemic infantile paralysis pre- 
sents a much greater variety than older descriptions attributed 
to this disease. This outbreak is a further proof that the dis- 
ease may settle in any part of the central nervous system and 
that it is by no means an affection_ limited to infancy and child- 
hood. The study of these cases illustrates how essential it is 
that the description of this disease must be revised, not only in 
regard to the symptomatology of the paralytic stage, but also 
to the symptoms of onset. Formerly the opinion prevailed that 
the prodromal symptoms are in the great majority of the cases 
only very slight and of short duration. The "morning paral- 



Studies in Infantile Paralysis 21 

ysis" of West (I. c. a child with hardly any previous symptoms 
of discomfort, wakes up paralyzed) used to l)e considered a typ- 
ical representative of the disease. During epidemics this form 
is extremely rare. The etiology of the early symptoms alone — 
formerly rather neglected — has gained the greatest importance 
siiice the infectious character of the disease became known. A 
diagnosis before the development of the paralysis is the aim of 
the physician of today, because early diagnosis means early 
isolation. 

Symptoms of Onset. 

In most instances the history obtained of the onset was some-: 
thing as follows : The child was irritable or drowsy for several 
days, had loss of appetite and marked constipation, fever of 
varying intensity, then, after several days, involvment of the 
nervous s^'stem until local symptoms set in, followed by paral- 
ysis. These general symptoms varied in the different cases. 
The more common ones were: Fever, headache, pain and stiff- 
ness of neck, pain and increased sensibility of the extremities 
and along the back, and constipation. Diarrhea, vomiting and 
symptoms from the upper air passages, convulsions, uncon- 
sciousness, belonged to the rarer occurrences. Disturbances of 
the bladder, formerly considered exceptional in this disease, 
were rather frequently observed. There is not a single case in 
the series with involvment of the anal sphincter. Intense pains 
were especially common and frequently persisted for weeks after 
a full developemnt of the disease. Photophobia of a marked 
degree has been reported in some cases. 

Paralytic Stage. 

These various symptoms lasted in a more or less marked de- 
gree for irregular periods of time, sometimes over two weeks 
until the symptoms of paralysis appeared. This usually came 
on slowly, gradually reaching to its fullest extent. For in- 
stance, a weakness in one leg would appear, developing after 
some days into a complete paralysis, which subsequently grad- 
ually attacked other parts of the body. Usually the initial 



2^ Washington State Board of Health 

symptoms had already subsided when the first signs of paralysis 
appeared, but occasionally fever and severe general symptoms 
persisted for a considerable period of time after onset of paral- 
ysis. Early disappearance of the knee jerk has been observed 
several times in the spinal form, often before actual paralysis 
appeared, and is sometimes the only symptom of the involvment 
of the opposite side. 

Symptomatology According to Wickman's Classification. 

Wickman, to whom we owe much in regard to our recent 
knowledge of this disease, classifies the different forms of the 
affection as follows : 

I. Spinal form. 

II. Landr3''s paralysis. 

III. The bulbar or pontine form. 
ly. Cerebral or encephalitic form. 
\. The ataxic form. 

Yl. Polyneuritic form. 
VII. Meningitic form. 
YUl. Abortive form. 

We decided to follow this classification because it illustrates 
best the variety in regard to localization. 

Spinal Form. 

This form, formerly known as t3^pical infantile paralysis, 
does not need much explanation. It represents the old flaccid 
paralysis. In this epidemic there is the usual prevalence of the 
classical localizations of the paralysis in arms and legs, as men- 
tioned in all the text books, and likewise the predominance of 
paralysis in the lower extremities. Among the muscles rarely 
attacked, we may note paralysis of the muscles of neck and 
back, of the flexors of the legs and extensors of the arms, and of 
the abdominal muscles. All these localizations were rare, es- 
pecially the last one, which has been reported as comparatively 
common during other epidemics. There was only one instance 
of paralysis of the calf muscles of the leg and no isolated 
parah^sis of the forearm muscles. 



Studies in Infantile Paralysis 23 

Generally the paralysis was Diuch more extensive in the be- 
ginning and was finally restricted to smaller groups of muscles, 
probably owing to the subsidence of the edema. 

A crossed paralysis, i. e., left-sided paralysis of one extremity 
witli a right-sided paralysis of the other, or vice versa, was 
comparatively frequent. 

Landry's Type. 

Landry's paralysis, described in all older text books as a sep- 
arate disease of the spinal cord, either ascending or descending, 
is now generally acknowledged to belong to this disease in most 
instances. But the separation fronii the spinal form is a rather 
arbitrarj^ one. There have been observed so many cases w^here 
the disease settled either ascending or descending in different 
parts of the cord, that this name is reserved for the cases in 
which the accompanying involvment of the respiratory centers 
became fatal. The rest of the cases, where this involvment is 
only temporary, belongs to the spinal type. 

Illustrative Case Landry Type. 

As a typical case may be considered the following: 
Werner A., 14 years. For three days fever and severe con- 
stipation. On third da^^ paralysis of both legs, next day as- 
cending to abdominal and thoracic muscles. On the fifth day 
death from respiratory failure. 

The disease is only found among older individuals. Some 
cases are reported in the literature where this symptom complex 
has been found without any central lesion, showing only changes 
in the peripheral nerves. 

Bulbar or Pontine Form. 

Here it is important to differentiate between the type "A," 
with affections of the muscles of the cerebral nerves combined 
with spinal lesions, and type "B," wherein cerebral nerves only 
are affected. 

Esther H., 4 years. Illustration type "A." Fever, intense 
headache, photophobia, slight pharyngitis. On the third day. 



24 Washington State Board of Health 

central facial palsy and paralysis of the ileopsoas on the right 
side. At present, only slight paralysis of the second and third 
branch of the nerve facialis. Leg free. 

William C, 6 years. Illustration type "B." Fever, head- 
ache, constipation, stiff neck. The child was unconscious for 
several days. Difficulty in breathing. Inability to swallow. 
For eight days loss of hearing and speech. On the eighth day 
right facial palsy. Difficulty of mastication. Facial and hy- 
poglossal palsy persisted for six weeks. Complete recovery. 

Encephalitic Type. 

This, the old polioencephalitis, has been very rare. 

Illustration : Margaret W., 9 months. Fever, constipation, 
convulsions, vomiting, conjugate de\4ation. On the second 
day paralysis of left arm and leg, both of the spastic type, with 
increased reflexes. After four more days complete recovery. 

Ataxic Form. 

No cases observed. Ataxia has been reported only once, and 
here it was impossible to state where the ataxia originated. Al- 
together the justification of the separation of this form is 
Very doubtful, because ataxia can be of various origins. 

Meningitic Form. 

The tremendous diagnostic difficulties arising in cases of this 
kind will be discussed later. 

The frequent participation of the meninges during the dis- 
ease is proven. 

Illustration; Evelyn H., 9 years. Fever, headache, vertigo, 
photophobia, propulsive vomiting. On the second day : double 
vision (right int. paralyzed on left eye). Left leg entirely 
paralyzed. (No reflexes). Right leg weak (reflex delayed). 
Gradual recovery, with the exception of the eye muscle. 

This case may not be a pure m>eningitis case, but the men- 
ingeal symptoms predominate. Pure cases have not been re- 
ported. 



Studies in Infantile Paralysis S5 

Folyneuritic Form. 

It ]i;is been already mentioned that affections of the peripheral 
nerves only have been proven by post-mortems. The picture so 
arising may be an extremely complicated one and only an 
autopsy may make a differentiation possible from a central 
lesion. This type, if accepted, may explain some cases of iso- 
lated facial paralysis, especially during epidemics. 

Case. 

Mildred W., 5 years. Slight sore throat, fever for one 
week. On the -second day, facial paralysis right side. Almost 
complete recovery. This case took place in a little community 
where a comparatively large number of typical cases were ob- 
served. 

Pain alone does not justify a diagnosis of the polyneuritic 
type, because pain may be of central origin. We cannot report 
a typical case of this form, but the following case gives symp- 
toms which may be suggestive of a participation of the periph- 
eral nerves : 

Case. 

Walter S., 7 years. Fever, headache, nausea, vomiting, con- 
stipation. Fever lasted for 7 days. During this time extreme 
pain, especially along the legs, to such an extent that poly- 
neuritis was diagnosed. Then paralysis of both legs appeared 
and paralysis of right abdominal muscles. Some weeks later, 
legs perfectly free, but a marked atrophy of entire right leg 
and hip. 

How far such a marked atrophy with recovered function can 
be attributed to the participation of peripheral nerves can only 
be proven b}' post-mprtems. 

Abortive Form. 

It is now generally believed that during epidemics a great 
many cases occur with the various initial symptoms but without 
development of a paralysis. This knowledge is of great im- 
portance from an epidemiological standpoint and this point 



26 Washington State Board of Health 

should be closely looked for during future epidemics. In our 
epidemic the physicians in general have not prepared for this 
form, and our information is mostly based on retrospective 
diagnosis. But, even after careful and sceptical investigation, 
it must be confessed that there have been reported quite a num- 
ber of cases both In the same families with typical cases or in 
neighboring houses, which are rather more than suggestive. 
This coincidence of timie, together with faint symptoms of tem- 
porary weakness in the extremities and pain, have been the basis 
of classifying a number of cases as belonging to this group, 
but an exact diagnosis is generally Impossible. Under espec- 
ially favorable circumstances a diagnosis can be and has been 
made. In the blood serum of every person having survived an 
attack of this disease, anti-bodies are formed which have power 
to bind the virus in vitro. If infectious material Is mixed with 
the serum of a doubtful case In a test tube, the serum will neu- 
tralize the virus and render it harmless for the monkey If the 
individual has really had the disease. 

Wickman classifies the abortive forms : 

1. Cases running under the picture of a general infection. 

2. Cases with symptoms suggestive of Involvment of the 
meninges. 

S. Cases with pronounced pains. (Influenza-like). 
4. Cases with gastro-Intestlnal troubles. 

Illustrations of Abortive Cases. 

As an illustration of the class of cases that have been re- 
garded in this investigation as probable abortive cases, the fol- 
lowing niiay be offered: 

Four families. A., B., C, and D., all living close together In 
an isolated rural section. Families A. and B. each have three, 
Families C. two, and D. four children, all under 10 years. One 
unquestionably severe case occurred In each of the two families, 
and in one of these a second child became sick a week later with 
the same early symptoms as the positive case, but no paralysis 
developed. In between these two positive cases there was sick- 
ness among the children of both the other families. 



Studies in Infantile Paralysis 27 

Albert S., l^^ years, family "C," taken ill two weeks after 
onset of positive case in family "A," with nausea, constipation, 
fever, headache, lasting two days. One week later relapse, \ 
same symptoms folloAved by weakness of legs for one week. ^" 
Slie^ht tenderness of back. Reflexes not tested. Perfect re- 
covery. 

In family "D,*' three of the children exhibited similar symp- 
toms, being taken sick at about six days in between each one. 
The note on the first taken ill is typical of the others also. 

Valborg S., family "S," 5 years, taken sick same day as first 
child of family "C," very close neighbors. Initial symptoms, 
vomiting, headache, diarrhea and fever. In bed two days. One 
week later return of headache and fever with constipation. In 
bed three da^-s. When she got up had lost control of legs. Con- j 
dition persisted for three days, then entirel}^ cleared up. 

DIAGNOSIS. 

It has been previously mentioned how important is an early 
diagnosis before the appearance of paralysis, both from epi- 
demiologic and therapeutic standpoints. A future drug or 
serum treatment can only be of use before the damage is com- 
pleted. The clinical picture of the prodromal and early symp- 
toms is vague. Symptoms of striking similarity can be ob- 
served during gastro-enteritis of children frequently. So it is 
quite natural that exact diagnostic help was sought through 
laboratory experimentation. The ability to transmit this dis- 
ease to monkeys made early and continuous observations possi- 
ble. The result, however, is very meagre. The examinations 
of the blood proved to be worthless in regard to specific changes. 
Likewise a serum test similar to the Wassermann test. 

A micro-organism could not be found, the urine did not show 
any characteristic changes, but the cerebro-spinal fluid showed 
some changes even before the appearance of the paral3^sis, which 
may furnish useful diagnostic points in some cases. The pres- 
sure is slightly increased, the fluid is usually clear (opalescent 
occasionall}^) and shows occasionally a fibrin clot. It contains 



Washington State Board of Health 



an increased amount of cells, mostly lymphocytes. These find- 
mgs will prove useless whenever there is reason to suspect tuber- 
cular meningitis, which may present the same picture. But a 
differentiation from cerebro-spinal meningitis can be easily made. 

The study of the early symptoms does not furnish any spe- 
cific diagnostic data. The peculiarity of the disease, previously 
noted, of attacking any part of the central nervous system, ex- 
plains the great variety of the early symptoms. This fact also 
explains why w^e have to give up the idea that the paralysis must 
necessarily be flaccid. It is not only possible to obtain exag- 
gerated reflexes in certain types, but also that on the same pa- 
tient both exaggeration and absence of reflexes may be found. 

Early disappearance of the reflexes in the spinal form seems 
to be a frequent and early symptom, but the difficulty of testing 
reflexes in young children has to be considered. 

Concluding we can only say that infantile paralysis has to be 
included by every physician in his diagnostic reflections at the 
bedside of a child with severe general symptoms. He will have 
to remember that these general symptom's may precede the pa- 
ralysis for weeks, that absence of reflexes are suspicious, that 
spinal puncture may assist in quite a number of cases — but, that 
an exact diagnosis will be impossible before appearance of pa- 
ralysis. After that and with a good history the diagnosis is 
easy, but it is not impossible that we are going too far at the 
present time and are including independent central nervous sys- 
tem affections in this classification. The infrequency^ with 
which a positive diagnosis can be made in the abortive cases has 
been frequently mentioned. 

TREATMENT. 

Treatment Acute Stage. 

During the acute stage treatment should be directed toward 
obtaining complete rest. The bowels should be opened and 
free elimination obtained. The irritability, muscular tender- 
ness and restlessness can be controlled to a considerable extent 
by warm baths, which relieve pain and produce sleep. Tepid 



Studies in Infantile Paralysis 29 

water sponge baths are useful as an antip^^rctic. Cupping or 
counter irritation with either extreme heat or cold is of doubtful 
nature for the relief of intra-spinal congestion. The diet 
should be light and nutritious. Massage during the acute 
stage, or while muscular tenderness is present, is distinctly con- 
tra-indicated, and its injudicious use at this time may do pos- 
itive harm. Hypnotics may be used to advantage, but may do 
positive harm in paralysis of the medullary type. The abdo- 
men should be closely watched for evidence of bladder disten- 
sion until it is obvious that the function of micturition is nor- 
mal. There is no objection to the use of urotropin at this 
stage, although it is probably of much greater value as a pro- 
phylactic measure. The importance of using 1 per cent, solution 
of hydrogen peroxide as a spray, gargle or swab for the throat 
and nose has been considered in the section on prophylaxis. 

The acute stage may be regarded as having passed when the 
irritability, fever, and excessive muscular tenderness have sub- 
sided, in spite of the fact that there commonly is sensitiveness 
on pressure along the nerve tracks for some time longer. Even 
at this earh' stage attention should be directed toward prexen- 
tion of deformity, which watchfulness must be continued for 
mionths to come. This is begun by protecting the paralyzed 
muscles from over stretching either by gravity or pressure. 
This is done by an easily removable splint or a pillow. Massage 
and passive motion may be instituted at this stage to advantage 
and well-directed exercises are often indulged in with zest which 
arouses a cheerful co-operation on the part of the child. Elec- 
tricity should not be used for treatment until the acute symp- 
toms have subsided and the extent of the residual paralysis be- 
comes more evident. It should never be used to the exclusion 
cf heat, massage, passive movement, or the supportive treat- 
ment of the paralyzed muscles. It is to be regretted tliat so 
important a procedure as the support of the paralvzed muscles 
so often is neglected, while electrical procedure is so universally 
employed. Parents are quick to sec in many instances that 
deformity is inevita})le from the habitual posture of the patient 



30 Washington State Board of Health 

unless mechanically prevented, and some practical means of ob- 
viating the difficulty have been devised. There were several 
interesting exanlples of such home-made devices in this series 
of cases. 

When the approximate extent of the residual paralysis can 
be determined, or some fixed deformity has been developed, 
operative procedures are indicated to correct the deformity or 
to use the remaining muscles to better advantage. 



Studies in Infantile Paralysis 31 



SECTION II. 

INFANTILE PARALYSIS AS OBSERVED IN THE 

STATE OF WASHINGTON IN THE SUMMER 

OF 1910. 

In presenting the results of our investigations in the State of 
Washington during the summer of 1910, it is pointed out that 
we have three classes of cases which- are presented in our tables. 

1st. The cases personally seen and studied by the authors 
of this report. 

2nd. Cases which were reported in considerable detail by 
the health officers or physicians, or both, upon the special 
blanks furnished for this purpose. 

3rd. Cases reported according to the records of the health 
departments of Seattle and Tacoma, which were neither re- 
ported on the special blanks to the State Board nor seen by the 
investigators. 

It will be noted that these three classes of cases must neces- 
sarily vary a great deal in the amount of data available from 
them. For this reason in all the different tables it is carefully 
stated which group of cases we are considering. 

First, the total number reported from all sources — 397. 

Second, cases in which the special reports were filled out by 
physicians or health officers, or both — 185. 

Third, the number studied by the special investigators — 146. 

All these different classes are utilized, some being available for 
one purpose and some for another. 

Diagnostic Standard, 

It is not claimed that all of these reports, even those studied 
by the investigators — 146 cases — are beyond question cases of 
infantile paralysis, and those which the investigators considered 
doubtful are classed by themselves in all tables of this series. 

The first minimum diagnostic standard adopted was the ex- 



32 Washington State Board of Health 

istence of an actual paralysis when investigated. As it was 
soon determined that many reported cases could not be seen 
for several months after their onset, it was apparent that 
this standard could not be adopted without excluding some 
positive cases. When there was a definite histor}^ obtained from 
both the family and physician of paralysis, which in several in- 
stances extended for weeks, although no paralysis was observed 
at the time of investigation, these were collected as positive 
cases, although their total number was not large. 

The general impression of all the health departments of the 
larger cities and nearly all of the county health officers, seems 
to be that there were many more cases of undoubted infantile 
paralysis in existence than were reported. 

It is noteworthy how few were the cases in our own series 
reported as infantile paralysis by the physician originally that 
could be classed as doubtful by the investigators later. Doubt- 
less the great increase in the amount of literature upon the sub- 
ject in recent years has been one reason why the physicians 
diagnosed in our series so much more accurately than has been 
the case as reported by several other previous investigators. 

DISTRIBUTION OF CASES. 

An analysis of the cases of infantile paralysis reported in 
the State of Washington in 1910, shows that there was no sec- 
tion of the State that was predominatingly affected, although 
there are some sections where the disease was surprisingly in- 
frequent or entirely absent. 

DISTRIBUTION OF CASES BY COUNTIES AND CITIES. 

Counties. Population No. of Incidence 

1910 Cases per 100.000 

Adams 10,920 5 45.5 

Asotin 5,831 3 51.3 

Benton 7,937 4 50.0 

Chehalis 35,590 1 2.8 

Chelan 15,104 6 39.7 

Clallam 6,735 1 14.8 

Clarke 26,115 11 41.8 

Columbia 7,042 00.0 

Cowlitz 12,561 4 31.6 

Douglas 9,227 1 10.8 

Ferry 4,800 00.0 



Studies in Infantile Paralysis 



Distribution of Cases — Concluded. 

Counties. Population No. of Incidence 

1910 Cases per 100,000 

Franklin 5,153 00.0 

Grant 8,695 3 34.5 

Garfield 4,199 5 119.0 

Island 4,704 1 21.2 

Jefferson 8,337 4 47.6 

King (exclusive of Seattle).... 47,444 29 60.9 

Kitsap 17,647 7 39.2 

Kittitas 18,561 3 16.1 

Klickitat 10,180 00.0 

Lewis 32,127 8 24.8 

Lincoln 17,539 15 85.5 

Mason 5,166 00.0 

Okanogan 12,887 10 77.0 

Pacific 12,532 17 134.3 

Pierce (exclusive of Tacoma) . . 37,069 9 24.2 

San Juan 3,603 00.0 

Skagit 29,241 3 10.2 

Skamania 2,877 4 138.8 

Snohomish (exclus. of Everett) 34,395 7 20.3 

Spokane (exclusive of Spokane) 35,002 13 36.4 

Stevens 25,297 00.0 

Thurston 17,581 1 5.7 

Wahkiakum 3,285 00.0 

Walla Walla 31,931 6 18.6 

Whatcom 25,213 4 15.6 

Whitman 33,280 6 18.0 

Yakima 41,709 11 26.3 

Cities of First Class: 

Bellingham 24,298 7 28.7 

Everett 24,814 1 4.03 

Seattle 237,194 108 45.3 

Spokane 104,402 21 19.9 

Tacoma 83,743 40 48.0 

Urban and Rural. 

The five cities of the first class, representing a little less 
than half of the total population, reported a total of 179 cases. 
These figures indicate that there was practically an even dis- 
tribution of cases between the larger cities and the smaller cities 
and rural districts. For approximate estimates we may place 
the population of the five large cities at 500,000 and the re- 
inainder of the State at 600,000. With these figures we find 
the proportion of cases arc 179 to 500,000 people (urban), 
and 218 to 600,000 people (rural or in cities of less than 
20,000). 

-3 



84 Washmgton State Board of Health 

Physical Geography. 

A distribution between the two sides of the state, which are 
sharply divided according to their chmate and physical geog- 
raphy, the division occurring in the line of the Cascade Moun- 
tains, shows that the proportion of cases between the east and 
west sides of the State was almost exactly equal proportionately 
to the population. This observation is interesting in view of 
the theory that excessive dryness and dust are two of the prin- 
cipal factors in the causation of the disease. The eastern por- 
tion of the State being largely semi-arid in character with a 
correspondingly greater degree of dryness and strong winds, 
carrying dust, it might be predicted of infantile paralysis in 
the eastern portion of the State would proportionately exceed 
that in the western portion, if the prevalence of the disease were 
miarkedly affected by climatic conditions. 

There were 120 cases reported from the eastern portion of the 
State, with a population of approximately 400,000, and 277 
cases reported from the western portion of the State, or coastal 
region, with a population of about 700,000, and including in 
the last division all the cities of the first class, with the excep- 
tion of Spokane. 

The accompanying outline map shows exactly the distribu- 
tion of the cases as reported by each county and the cities of 
the first class, which are tabulated apart from the counties in 
which they are situated. There are some features of this dis- 
tribution which are of sufficient' special interest to warrant in- 
dividual mention. 

Distribution in Cities of the First Class. 

Among the cities of the first class, Everett is conspicuous for 
the few cases reported, having altogether only three — one of 
which was brought into the city from a neighboring town. 

Among the other large cities Tacoma appears to have been 
more affected than either Seattle or Spokane in proportion to 
its population, since the Tacoma health office reports a total of 
40 cases, with the remark that they do not*consider their rec- 
ords complete; while the Seattle health office is of the opinion 



36 Washington State Board of Health 

that practically every case occurring in the city — a total of 
108 cases — was seen and investigated by either the city or state 
investigators. 

The disease would appear to have been less prevalent in 
Spokane than in either of the two larger Coast cities, although 
there is no certainty that the report of cases from Spokane is 
complete. 

Chehalis and Pacific Counties. 

Among counties, Pacific county is conspicuous for the se- 
verity of the infection in proportion to its population, and 
Chehalis county, which lies directly north of Pacific and con- 
tains the populous and thriving cities of Aberdeen and Hoquiam, 
besides several smaller towns, was conspicuous for the almost en- 
tire absence of the disease. These two counties considered to- 
gether are striking examples of the obscurity which surrounds 
the means of transmission of infantile paralysis. Their cli- 
matic conditions are practically the same ; each county is trav- 
ersed by large streams which flow into large bays — arms of the 
Pacific ocean ; they are both low-h'ing in those portions of the 
two counties where towns and villages exist, and the two streams 
along which nearly all their respective settlements are located 
are only about 25 or 35 miles apart. Chehalis county, as has 
already been mentioned, is by far the more populous, containing 
about three times as many people as Pacific, with a correspond- 
ingly greater amount of intercourse and travel between it and 
other portions of the State. Yet but one case of the disease was 
reported from Chehalis county throughout the entire season, 
while no less than 23 cases occurred in the neighboring county, 
nearly all either in or in the immediate vicinity of the two cities 
of South Bend and Raymond. 

Eastern Counties. 

Whitman and Walla Walla counties, and . Columbia county 
in the extreme southeast of the State, reported altogether but 
very few cases, which is all the more remarkable when it is 
borne in mind that both in the counties of this State immediately 



Studies in Infantile Paralysis 37 

adjacent to them, viz., Spokane, Lincoln, Adams, Asotin, Gar- 
field and Benton, the disease was reported as quite prevalent in 
proportion to their population, and that the greatest intensity 
of the Idaho epidemic was noted in the section of that state 
lying but comparatively a short distance from the Washington 
line. 

It is also notew^orthy that two of the five cases reported from 
Walla Walla county were first taken sick across the line in 
Oregon. 

The comparatively^ remote and little developed county of 
Okanogan reported an unusually" large number of cases in pro- 
portion to its population. It has been a matter of great regret 
to the investigators that on account of the amount of time that 
would necessarily be involved, and the difficulties of transporta- 
tion, it was not feasible to personally see the cases reported 
from this county. Several of. the reports of the local ph^^si- 
cians brought out very interesting features in regard to the 
disease as it occurred in this section of the State. 

San Juan. 

The county of San Juan presents some interesting negative 
features. This county, lying a short distance from the main 
land, is composed of a group of small islands. It is much fre- 
quented by summer ^^sitors and in that season enjoys free com- 
munication with the adjacent cities on the Sound and of British 
Columbia. So far as can be ascertained it was entirely exempt 
from infantile paralysis, in spite of the fact that cases were re- 
ported from Vancouver Island, the mainland of British Columbia, 
and the nearby counties of Washington. 



38 



Washington State Board of Health 



INCIDENCE OF THE DISEASE. 



Sex. 



In the entire series reported the figures show that there were 
202 males, 176 female, and 19 cases in which the sex was not 
stated. 

The following tables shows the sex distribution of the two 

groups of investigated, and detail reported but not investigated 

cases, respectively : 

( Males 77 

Investigated cases < Females 68 

( Not stated 1 14^ 

( Males 98 

Reported cases \ Females 87 

Not stated 185 



331 
Age. 

The table for age periods shows that the incidence of the dis- 
ease was greatest between the ages of 2 and 3 years, which cor- 
roborates the findings of the Massachusetts investigation for 
1909: 



Age. 


Cases. 


1 month ..... 


1 


2 months 


1 


6 months 


1 


7 months 


1 


8 months .... 


2 


9 months .... 


5 


10 months 


2 


11 months 


5 


12 months 


6 


13 months .... 


2 


14 months 


2 



15 months 6 

16 months 6 

17 months 4 

18 months 11 

20 months 4 

21 months 2 

2 years 44 

3 years 38 

4 years 33 

5 years 21 

6 years 21 

7 years 22 

8 years 9 



Age. 



Cases. 



9 
10 



years 5 

years 10 

11 years 8 

12 years 4 

13 years 5 

14 years 4 

15 years 4 

16 years 3 

18 years 3 

19 years 4 

20 years 2 

21 years 2 

22 years 5 

23 years 1 

24 years 2 

25 years 

26 years 3 

27 years 1 

28 years 2 

32 years 1 

44 years 1 

46 years 1 

55 years 1 

Not stated 11 



Total 331 



Studies in Infantile Paralysis 



Mortality. 

The problem of obtaining entirely accurate percentages of 
fatal cases of infantile paralysis is apparently a hopeless one. 
This same difficulty must exist in every epidemic. It was found 
that the total numb e r of deaths returned. on death certificates 
presented a very wide discrepancy when compared with the 
number of fatal cases discovered in the investigated and re- 
ported series. The death certificates may give a considerable 
number of fatal cases of undoubted infantile paralysis which 
were not reported to the State Board of Health as cases of the 
disease. On the other hand, there was such a general interest 
on the part of physicians that it is difficult to believe that there 
were so many clear cases not reported as the difference between 
these two death rates would indicate. 

The total number of death returns for the year 1910 with 
the cause of death given as infantile paralysis, for the entire 
State, was 76. Yet in the series of 8S1 cases reported or in- 
vestigated there were only 28 deaths. The difference between 
the sum of the cases in these two series and the total number, 
397 — 66 cases — represents those cases which were reported to 
the health departments of Seattle and Tacoma, in excess of the 
numbers studied in those two cities by the present investigators, 
From the extra series reported to the Seattle city health de- 
partmjent — 49 — there were 8 more fatal cases. It is impossible 
to tell from the Tacoma records exactly how many of their 
extra series of 17 cases were also fatal. But from the 381 
cases, representing the investigated series and the reported se- 
ries, plus the extra cases from the Seattle health department 
records, there were in all 36 deaths, which would give a mor- 
tality perecentage for the entire number of cases reported, 
with the exception of the small number in the Tacoma extra 
series, of 9.4%. But this leaves an unexplainable discrepancy 
between total mortality of the series studied and the number of 
cases returned on death certificates of nearly 40 deaths. Since 
it is very unlikely that the small extra Tacoma series can rep- 
resent more than two or three fatal cases at the outside, we are 



40 WaMngtofi State Board of Health 

more or less forced to the conclusion that several of the death 
certificates returned as infantile paralysis were far from clear 
cases of the disease clinically. Therefore, it would probably 
not give a fair picture of the fatality of the disease to utilize 
the official death returns ; but for the investigated and reported 
series — 331 cases in all — the deaths by ages have been accu- 
rately determined and are given in the following table, which 
gives an average mortality of 8.4% : 

MORTALITY BY AGES. 

Investigated Series, 146. Reported Series, 185'. Total, 331. 
Age. Cases. Deaths. Mortality 

Under 1 year 18 2 11.1% 

1 to 10 years 237 15 6.2% 

Over 10 years 60 11 18.3% 

Not stated 16 0.0% 

331 28 8.4% 

CLINICAL STUDIES. 

Tabulation of Early Symptoms. 



146 Cases. 



Fever 106 

Pain 58 

Tenderness 51 

Vomiting 54 

Constipation 61 

Diarrhoea 14 

Retraction of head 29 

Headache 65 

Delirium 2 

Nausea 6 

Twitching of limbs 1 

Naso-pharyngeal symptoms 16V 

Bronchitis ■ 4 

Unconscious 1 

Convulsions 3 

Languid, sleepiness and Weakness 8 

Blindness 1 

Vertigo . 1 

Nose bleed 1 

Lost voice 1 

Coated tongue ..... 2 

Stiff neck 8 

Photophobia 5 

Tonsilitis 3 

Jaundice ^ 1 

Indigestion 2 

Tenesmus 1 



Studies in Infantile Paralysis 41 

It is notable that the most striking- feature in regard to the 
early s^-mptoms is the great preponderance of cases in which 
distinct fever appeared — 106 cases. 

In 61 cases constipation was distinctly noted among the early 
symptoms, and in only 14 was there diarrhoea. 

Deducting the group of 10 abortive or doubtful cases of our 
total series, the relative frequency with which constipation was 
noted as an early symptom, 61 cases out of 136 positive cases, 
in contrast to the very few cases in which diarrhea was noted — 
14 cases — is very striking and conforms to the observations ob-/ 
tained in most other recent outbreaks. ' 

It is also notable that pain, tenderness and vomiting were 
each reported as early symptoms with about equal frequency. 

Respiratory and Early Mental Symptoms. 

Special attention was paid to symptoms of infection of the 
upper respiratory passages just previous or coincident with the 
onset. The figures obtained from this inquiry are rather inter- 
esting in the light of the theory that the disease is introduced 
into the body through the naso-pharyngeal tract. In this en- 
tire group, counting in even the 10 doubtful or abortive cases, 
pharyngitis was only recorded as having been present in 32 
cases and coryza in 10 cases, as follows: 

Pharyngitis 32 

Absent 114 

Coryza 10 

Absent 136 . 

A special note was also made in regard to mental symptoms 
just preceding or coincident with the onset. The result of this 
investigation is as follows : 

Irritability 35 

Weak ( general ) 1 

Tired 2 

Apathy 2 

Maniacal 1 

Nervous (very) 1 

No change in disposition 104 

146 ^ 
The important lesson to be drawn from this tabulation is 
that these last symptoms did not occur with a sufficient degree 



42 Washington State Board of Health 

of constancy to be considered as diagnostic, in spite of the em- 
phasis that has sometimes been placed upon them. 

Intestinal and Bladder Disturbances. 

. BLADDER DISTURBANCES. 

y None 80 

Retention 18 

Difficulty 15 

Frequency 3 

Incontinence 5 • 

Not stated 15 

136 cases 
Doubtful or abortive cases 10 

146 
INTESTINAL DISTURBANCES. 

Constipation 68 

Diarrhea 12 

Involuntary stools 

None 22 

Not stated 30 

Diarrhea, later constipation 2 

Constipation followed by diarrhea 2 

186 cases 
\ Doubtful or abortive cases 10 

146 

In 68 cases it was noted that constipation was the rule 
throughout the course of the acute attack. 

In 12 cases diarrhea was noted, and in two cases each it was 
noted that the attack came on with one condition and later 
shifted to the other. 

There was a definite note that there was no disturbance of 
the bowels whatever in 22 cases. In 30 cases no note was made 
as to the condition of the intestines. 

Careful inquiry was also made in regard to bladder dis- 
turbances. It was found that in 80 cases no disturbance of 
urination was noted whatever; that in 18 cases there was actual 
retention ; in 15 cases difficulty in voiding but not sufficient to be 
classed as retention. In 3 cases there was an increased fre- 
quency, and in 5 cases a loss of bladder control. On 15 cases 
no note was made in regard to bladder condition. 

These figures, which are very similar to those obtained in 
other investigations, would indicate that retention and diffi- 



Studies in Infantile Paralysis 43 

culty, when present, may be suggestive of infantile paralysis, 
but that they are so inconstant that their absence is of no 
diagnostic value; and moreover, from' the comparatively small 
number in which incontinence was noted, it would further in- 
dicate that in very few of the cases were the spincters directly 
involved. 

It is to be noted that in our series, although there were 5 cases 
suffering from incontinence of urine, that in no single case was 
involuntary passage of stools reported. 

Pain and Tenderness. \^ 

The cases investigated would indicate that pain or tenderness 

was present at some stage in a great majority of cases, and it is 

well to emphasize its importance among the few really reliable 

early signs. 

- PAIN AND TENDERNESS. 

Pain and tenderness v/as present in... 98 cases 

Pain and tenderness was absent in 25 cases 

Pain and tenderness was not stated in. . 13 cases 

136 cases 
Doubtful or abortive cases 10 

146 cases 
In this connection it is interesting to note the length of time 
in which the pain and tenderness lasted, as is shown by the fol- 
lowing table : 

One day or less 1 case 

Two days 4 cases 

Three days 4 cases 

Pour days 9 cases 

Five days 1 case 

One week 8 cases 

One to two weeks 8 cases 

Two to three weeks 21 cases 

Three to four weeks 7 cases 

Four to five weeks 15 cases 

Five to seven weeks 4 cases 

Seven to eight weeks 1 case 

Eight to nine weeks 4 cases 

Still persisting 7 cases 

A few days 4 cases 

No pain or tenderness 25 cases 

Not stated 13 cases 

136 cases 
Doubtful or abortive cases 10 

146 cases 



44 Washington State Board of Health 

This would indicate that the duration of pain or tenderness is 
usually from one week to one month, while in a considerable 
number of cases (25) it is stated that no pain or tenderness was 
observed at any time during the course of the disease. 

Duration of Fever. 

The following table shows the duration of fever in the 146 

cases investigated. In this table the doubtful or abortive cases, 

which are separately classified in nearly all of our other tables, 

are included: 

DURATION OF FEVER. 
■^ yo day 2 cases 

1 day 5 cases 

2 days 9 cases 

3 days 25 cases 

4 days 18 cases 

5 days 13 cases 

6 days 5 cases 

7 days 27 cases 

8 days 1 case 

9 days 1 case 

10 days 5 cases _ 

2 weeks 3 cases , , 

2 to 3 weeks 1 case '' 

No fever 4 cases 

Few days 2 cases 

Not stated 25 cases 

146 cases 

Time of Onset of Paralysis After Onset of Fever. 

Another point which was sought after in hopes that it might 

be of some importance, was the length of time after the onset of 

fever before the appearance of paralysis. The following table 

shows the tabulation of cases in this respect : 

% day 7 

1 day 11 

2 days 25 

3 days 27 

4 days 15 

5 days 17 

6 days 5 

7 days 6 

8 days 2 

10 days 1 

2 weeks •. 2 

Few days 2 

No fever noted 4 

Not stated 12 

Doubtful or abortive cases 10 

146 



Studies in Infantile Paralysis 45 



This table corroborates completely the experience of most 
observers; namely, that in the vast majority of cases the pa- 
ralysis will come on within five days, although it may be delayed 
for many days. 

The group which is given as "not stated" (12) may appear 
undulv large, but these are cases in which no physician was 
called early, or for some other reason it was impossible to get a 
definite history of either the presence or absence of the fever. 

GENERAL SURROUNDINGS OF PATIENTS. 

146 Cases. 

Under this heading a variety of data was sought which have 
been considered by observers to play some etiologic factor in the 
transmission and causation of infantile paralysis. 

The following tables are largely self-explanatory. The ob- 
servers do not feel that the data drawn from them would tend 
to support the theories wliich have been advanced advocating 
that such things as situation of house, its surroundings, near- 
ness to water, sanitary conditions, character of water supply, 
sewage disposal, etc., have any direct bearing upon the prev- 
alence or absence of the disease. 

It is well to remember that many of the points which have 
been brought out in regard to nearness to water or railroads, 
would in themselves have no epidemiological bearing unless we 
knew the proportion of the inhabitants of any community, or of 
the entire State, which lived within certain distances from a 
railroad, or stream, pond or beach, compared with the number 
of people who live at a considerable distance from these ; and 
this is a point which it is impossible to determine. 

Character of House. 

Detached house 112 

Tenement house 10 

Xot given 7 

House boat 2 

Detached with store below 2 

Tent 2 

Institution 1 

136 
Doubtful or abortive cases 10 

146 146 cases 



46 



Washington State Board of Health 



Location of House. 

High 41 

Medium 35 

Low 46 

Not given 12 

House boat 2 

136 
Doubtful or abortive cases 10 

146 146 cases 

Sanitary Conditions of House. 

Excellent 10 

Good 41 

Fair 58 

Bad 17 

Not stated 10 

136 
Doubtful or abortive cases 10 

146 146 cases 

Relation to Dust. 

None 12 

Very little 9 

Moderate 16 

Considerable 88 

Not stated 11 

136 
Doubtful or abortive cases 10 

146 146 cases 
Screejis. 

Present 46 

Absent 51 

Not stated 39 

136 
Doubtful or abortive cases 10 

146 146 cases 
Water Supply. 

City water 72 

. Well 40 

Spring 13 

Irrigation water 1 

Cistern 1 

Not stated 8 

Water brought in barrels 1 

136 
Doubtful or abortive cases 10 

146 146 cases 



Studies in Infantile Paralysis 47 



Sewage Disposal. 



City sewer 46 

Cesspool 11 

Privy 67 

Otherwise 2 

Not given 8 

136 

Doubtful or abortive cases 10 

146 146 cases 
Nearness to Railroad 

One-eighth mile 3 

One-fourth mile 9 

One-third mile 1 

One-half mile '. 7 

Three fourths mile 10 

1 mile 14 

1% miles 1 

11^ miles 4 

2 miles 5 

3 miles 1 

4 miles 1 

5 miles 1 

12 miles 1 

15 miles 1 

16 miles 1 

19 miles 1 

20 miles 1 

22 miles 2 

100 feet 1 

150 feet 1 

200 feet 1 

250 feet 1 

400 feet 3 

600 feet 1 

900 feet 2 

V2 block 2 

1 block 2 

2 blocks 3 

21/0 blocks 1 

3 blocks 1 

4 blocks 1 

6 blocks 2 

8 blocks 2 

100 yards 2 

200 yards 1 

300 yards 1 

350 yards' 1 

500 yards 1 

Few rods 1 

Several miles 2 

None 21 

Not stated 18 



48 Washington State Board of Health 

Domestic Animals. 

As has been previously stated, there is no data obtainable in 
the present outbreak of an authentic nature which would indi- 
cate that there was any close connection between an epidemic of 
paralysis among domestic animals in any neighborhood and the 
onset of infantile paralysis among human beings. 

The following table shows the data obtained relative to as- 
sociation with animals, the distribution of the animals kept, and 
sickness or paralysis among same, and families in which the dis- 
ease occurred: 

RELATION TO ANIMALS. 

No animals in 56 families 

Animals in 69 families 

Not stated 3 families 

128 families 
ANIMALS WERE DISTRIBUTED AS FOLLOWS. 

37 families had 1,514 hens 

17 families had 44 cows 

6 families had 23 pigs 

14 families had 78 horses 

35 families had 62 cats 

29 families had 37 dogs 

SICKNESS— CRIPPLED OR PARALYZED ANIMALS. 

Four families gave a history of sickness among hens, thus: 

(1) Many injured by horses in 2 families. 

(2) Swollen neck in one hen in 1 family. 

(3) Three hens were paralyzed in 1 family. 

(4) Several died of unknown causes in 1 family. 

Also 1 family had one dog paralyzed for 2 days one week before 
onset in child. 

CERTAIN SPECIAL CONDITIONS PRECEDING 
ATTACK. 

Certain factors have been held by both the medical profes- 
sion and the laity to have an important etiological bearing upon 
the occurrence of infantile paralysis. Some of these factors, 
such as trauma, have been furnished as an explanatory cause 
ever since biblical times, while others, as swimming and wading, 
have been brought out as a frequent occurrence just before 
onset of the attack, through the scientific investigations of 
other epidemics. 



Studies in Infantile Paralysis 



49 



For this purpose careful inquiry was made as to whether the 
patient had been either swimming or wading shortly before the 
attack, or whether there had been exposure to heat, cold or 
dampness, or history of an accident, fall or over exertion. 

The following tables give the results on these three factors : 

Swimming and Wading. 

Swimming 3 

Wading 3 

Swimming and wading 10 

Xo swimming or wading 118 

Not stated 2 

136 
Doubtful or abortive cases 10 

146 146 cases 
Exposure to Heat, Cold or Dampness. 

Heat 8 

Cold 1 

Dampness 4 

Cold and dampness 4 

Exposure but not stated to what exposed . . 3 

Xo exposure 60 

Not stated 56 

136 
Doubtful or abortive cases 10 

146 146 cases 
Accident^ Fall or Over Exertion. 

Accident 3 

Fall 8 

Over exertion 7 

None 111 

Not stated 7 

136 
Doubtful or abortive cases 10 

146 146 cases 
The Massachusetts report of 1909 emphasizes the fact that 
nearly one-half of their cases had been swimm^'ng or wading 
just before onset and in water contaminated more or less by 
sewage. Our figures do not show any such frequency in re- 
gard to swimming and wading. Also no such figures are shown 
in regard to frequency of exposure to cold or to dampness or 
heat. It is possible that different climatic conditions explain 
the discrepancies in this respect between the two groups of 



50 Washington State Board of Health 

cases, which are almost identical in numbers, and this is the 
more valuable since, in our opinion, it tends to disprove the 
theory that any of these factors have any specific bearing upon 
the occurrence of infantile paralysis. The climate of Puget 
Sound is so even or equable in the summer months that few 
people would be inclined to consider any conditions under which 
children might be placed as regards heat, cold or dampness as 
exceptional or unusual. The waters of Puget Sound region 
are so cold as to preclude any very common practice of allowing 
young children to wade in them except for very short periods 
during the summer months. Therefore, it would seem as if the 
striking difference between the frequency of these factors in 
the occurrence of the disease in Massachusetts and in Wash- 
ington is probably due to difference in climate, and, conse- 
quently, differences in out-of-door habits. It would not seem 
likely that these factors have any bearing upon the occurrence 
of the disease, but that they are purely accidental coincidences. 

POSSIBLE COMMUNICABILITY. 

(In Present Series). 

Throughout the progress of the investigation special atten- 
tion was directed to any instances of possible transmission. The 
accompanying table shows how comparatively seldom was there 
any occurrence of more than one case in the same family. It 
is especially noteworthy that in no instance was there more than 
two cases. The only apparent exception to the rule in both 
the investigated and reported series, were in certain few in- 
stances where there was a question of possible abortive case or 
cases in the same family along with one or more undoubted 
positive cases : 

Transmissibility Table. 146 Cases. 

FAMILIES WITH MORE THAN ONE CASE. 

120 families with 1 case 

8 families with 2 cases 

families with more than 2 cases cases 

128 136 . 

Abortive cases 10 

146 



Studies in Infantile Paralysis 



Contagion by Contact. , 

There were many interesting Instances of possible contagious- 
ness. Sonx of the most striking of these were reported care- 
fully by correspondence and have every right to be considered 
as authentic. But for the purpose of greater clearness, no 
cases outside the series of 146 investigated cases will be pre- 
sented. 

The following table shows the number of instances of ap- 
parent transmission from person to person : 

INSTANCES OP POSSIBLE CONTAGIOUSNESS. 

Direct contact with acute case in 10 cases 

Direct contact with a possible abortive case 9 cases 

Direct contact with a chronic and indirect contact with an 

acute case by third person 1 case 

Indirect contact by a third person with an acute case 3 cases 

23 cases 
Illustrative Cases. 

First of all, there was one case which was conspicuous as an 
illustration of how little infantile paralysis follows the ordinary 
course of contagion as usually occurs in the acute infections of 
children. This case occurred under conditions which would be 
ideal for transmission. 

The patient was a little girl seven years old, an inmate of a 
children's home in Seattle. There w^ere in all 200 children in 
the home. The patient had been in close contact with all the 
other inmates up to the time of taking to bed. She was then 
strictly isolated by the physician in charge. Not another case 
developed among the other children. The paralysis in this case 
was both extensive and intensive, it being one of the most pro- 
nounced of the entire series. 

A few of the best instances of possible transmission are here 
presented. In all these cases there can be no dogmatic asser- 
tion that any were directly secondary to others until more light 
is thrown upon the nature of the etiologic virus of infantile 
paralysis. However, they are so striking that from a priori 
grounds it is very difficult to conceive of their being only acci- 
dental coincidences. 



/^ 



52 Washington State Board of Health 

Illustration **^" — Water Trough Cases. 

These cases are two in number — a boy and a girl, cousins, 
aged 6 and 2 respectively. The boy was visiting the home of 
the little girl the week previous to their illness. During this 
week these two children played together and were most fond of 
playing in the watering trough which the cows used. The 
children did not get into the trough bodily but played with 
arn|s in the water and leaning over edge of trough. It is sug- 
gestive, at least, to note that in both instances the paralysis was 
of cervical and upper extremity type. A few days after the re- 
turn of the boy to his home in a neighboring city, the little girl 
came down with infantile paralysis. Four days from this time 
the boy at his home developed a case of the fulminating type. 
After the typical paralysis, as noted above, had developed, death 
ensued from respiratory paralysis two days from onset. The 
accompanying diagram roughly illustrates these cases. 



T«KEM SICK JULY 
DIED JULV iSlil 



II l| TROUGH. 

lAN^/ \. LUCY. 

MV<9 • TAKEN ILU JOl 



Illustration "5" — Family Group Association with Old Case. 

The second group illustrates an example of possible contagion 
both between closely associated acute cases and the association 
of both of these with an old case. It may faintly indicate the 
possibility of special family_susceptibility. The following dia- 
gram will sufficiently illustrate the conditions in this instance: 



FAMILY 'A FAIVIILV "" B " 
NORA. 5 VEARS. GUADVSa YEARS 
SICK AUGUST IStrj SICKSEP. ISI 
, riTHPR /"^"X /^^ ^. 2. OTHER 

-'^zh^ ft I ( 1 p^::^,^^- 




VICTOR. 2. YEARS BERTHA, OLD CASE 

SICK &iPT 3- f ^|^^|gi!^.''^'°''' 

CH/LOfi£/^ OF Fflr^lLY "/R'AND F/HVULy'b' C0US//^S AND CLOSE N£/OHBORS 



SKETCH OP PORTION OFVA5H0N ISLAND 



KEY 

POSITIVE CASES 




54 Washington State Board of Health 

Illustration "C" — Community Group (see sketch). 

The third group is interesting from the fact that it illustrates 
a group of both positive and doubtful or abortive cases, having^ 
a clear-cut community association, and thereby a possible com- 
mon means of transmission. All attended the same Sunday 
school, which was practically the only medium for the congre- 
gation of children at the season of the year in which the out- 
break occurred. These cases were on an island with only water 
transportation available, while at the same time, this section of 
the island was rather frequented by visitors from the cities of 
Seattle and Tacoma, where the disease was prevalent at the 
time. No direct instances could be found of any one from these 
cities visiting this neighborhood who had been in association 
with an infantile paralysis case, however. 

TABLE SHOWING DISTRIBUTION OF PARALYSIS. 

It is interesting to note the frequency with which the muscles 
of the head, face and deglutition are involved, as shown in the 
table, of the number of cases of the pure bulbar type, or with 
involvment of face or eye muscles : 

Left arm ( only ) 9 

Right arm (only) 8 

Right shoulder (only) 2 

Left shoulder (only) 2 

Right arm and right shoulder 1 

Both arms and back 1 

Left shoulder, right arm and back 1 

Left shoulder, back and abdomen 1 

Left shoulder, back and left leg 1 

Both arms, back and left leg 1 

Both arms, back and right leg 1 

Both arms, back and both legs 2 

Both arms and left leg 1 

Both arms and both legs 5 

Right arm and left leg 2 

Right arm and left leg 1 

Left arm and left leg 1 

; Left shoulder and both legs 1 

Abdomen (only) (atrophy) 1 

Right leg (only) 25 

Left leg (only) 18 

Both legs (only) 22 

Both legs and left arm 8 

Right leg and left hip 1 

Total right Hemiplegia 1 

Right arm, face and eye 1 



Studies in Infantile Paralysis 55 



Right face and right thigh 1 

Right face, tongue and right arm 1 

Left eye 1 

Face alone 1 

Face and strabismus 1 

Speech and strabismus 1 

Cerebral type 1 

Landry type 2 

Bulbar type 7 

Recovered cases without exact localization 2 

Abortive cases 10 

. . . 146 

In this scries in all there were 19 complete recoveries at the 
time investigated, or according to subsequent reports. It is 
certain that a considerable number of these cases show no signs 
of paralysis at the present time, extending from 10 months to a 
year from the time when first seen. At some future time the 
data will be sought upon this entire series as far as possible in 
order to determine how large a proportion of the series finally 
made complete recoveries. ^ 

SEASONAL PREVALENCE. 

Taking only the two groups, investigated and detailed re- 
ported cases, the occurrence of infantile paralysis by cases was 
reported as. follows : 

Month. Cases. 

January 3 

February 1 

March 1 

April 1 

May 6 

June 24 

July 58 

August 105 

September 67 

October 32 

November 11 

December 3 

Not stated 19 

Total 381 

The following table also gives the number of cases returned 
on the death certificates to the State Registrar as due to in- 
fantile paralysis for the same months, but since, as was pointed 
out in the section on mortality, there were only 28 fatal cases 



56 Washmgton State Board of Health 

in this group of 331, it is doubtful just how much reliabihty 
should be placed upon the validity of the diagnoses on these 
death certificates : 

Month. Deaths. 

January 

February 

March 

April 

May 

June 2 

July 1 

August 17 

September 21 

October 18 

November 9 

December 6 

Total 76 

As a matter of interest, the onset of the cases alone has been 
arranged according to months, segregated into the western and 
eastern divisions of the State, as per the following table: 

East. West. 

January 2 1 

February 1 

March 1 

April 1 

May 2 4 

June 17 7 

July 21 37 

August 30 75 

September 15 52 

October 11 21 

November 3 8 

December 3 

Not stated 8 11 

This seasonal distribution is very similar to that noted in 
other places, with some interesting departures in details. For 
instance, it may be noted by connparison of the two tables that 
the period of greatest prevalence in the eastern division of the 
State came on considerably earlier than in the western. While 
August was the month in which the greatest number of cases 
were reported on both sides of the State, yet it is very notable 
that the figures for August for the eastern division represent a 
very gradual increase over the two previous months, whereas in 
the western division of the State the number of cases rose very 
abruptly with the month of July and then again doubled for 



Studies in Infantile Paralysis 



5T 



the next month. The greatly increased prevalence of infantile 
paralysis in the late summer and early fall has been almost uni- 
versally noted during epidemics. 

There has been one marked exception in the United States to 
this rule, since House reported that in the epidemic in the Wil- 

Ch/1RT SHOWING TmE OF ONSET AND fVIORT/lLITY BY IYI0NTH5 . 

110 

100 
90 
80 
70 
60 
50 
40 
30 
ZO 
10 



.110 


JAN. 


FEB. 


IVIAR. 


APR. 


lYlAY 


JUNE 


JULY 


AUG. 


SEPT. 


OCT. 


NOV. 


DEC. 


100 
















A 










90 
















h 










80 
















\ 


\ 








70 
















\ 


\ 








80 














/ 




\ 








50 














/ 




\ 


y 






40 














/ 






\ 






30 












y 


/ 






\, 






20 












/ 










\ 




1 










y 


/ 




r 




^ 




\ 




. 








y 




/ 
/ 










A- 


CASES 


JAN. 
3 


FEB. 

f 


MAR. 
I 


APR. 
1 


lYIAY. 
6 


JUNE. 
24 


JULY 
57 


AUG. 
105 


SER 
67 


OCT 
32 


NOV. 
11 


DEC. 

3 


DEATHS 

















E 


1 


17 


21 


18 


9 


6 



Casas Qiuen as mporfea. Deaths as returned, on death eertihcstes. 
Note that deaths reported exceed cgses in December This means some cases 
-fa// ins /// /> previous mont/is rnsy haue ct/ed in December^ else that probably fh^re 
Luere several more cases in December f/iat were not reported- also that .some of diagnoses on 
-death cert/t/cates may haue been erroneous. 

lamette valley, in the fall of 1909, the disease did not reach its 
greatest prevalence until well after the establishment of the 
rainy season. But from the large number of outbreaks now 
reported, it is impossible not to be impressed with the fact that 
the disease has a true seasonal prevalence, 

A considerable number of factors might possibly be ad- 
vanced as having a possible relationship to the increased prev- 
alence of infantile paralysis at this period of the year. 



58 Washington State Board of Health 

The three that have received the most attention have been : 

1st. Insects, It has been suggested that since the season of 
greatest prevalence of infantile paralysis corresponds, approxi- 
mately, to the season of the maximum prevalence of many in- 
sects, that, therefore, it may be that the disease is transmitted 
through insect bites. This theory will have to fulfill many diffi- 
cult requirements before it can be very seriously urged, unless 
it can be corroborated as a result of laboratory experiments. 
The findings of Flexner that the virus can be retained for at 
least 48 hours in a negative condition by a fly's foot, are highly 
suggestive in this respect. 

2nd. Dust. Hill, of Minnesota, has been an active advocate 
of this theory. It is very suggestive at least to note that the 
outbreak in this state occurred during a season of unusual de- 
ficient precipitation of rain. Owing to the fact that the sum- 
mer season is a period of almost total absence of rainfall in the 
coastal region, as well as in the eastern division of Washington, 
the theory that dust is an active means of conveying the in- 
fected virus is practically reconcilable to the climatological data 
of this state. 

3rd. Travel. Richardson and Lovett have argued that the 
great increase of travel in the summer months may explain the 
greater prevalence of infantile paralysis during this season. 
It is also easily conceivable how this factor plays an important 
part in the transmission of the disease in this state, since there 
is an ever increasing amount of travel by tourists, especially 
from the middle west to the region of Puget Sound. These tour- 
ists begin to arrive about midsummer. Local traffic in the state 
is decidedly more active in the dry season than in the rainy. 
Especially is it true that there is a very considerable movement 
of people from the semi-arid region of the eastern sections to 
the coast during the heat of the summer season. 

Eastern investigators have frequently pointed out that there 
is a relation in the seasonal prevalence between infantile 
diarrhea and infantile paralysis. The evidence that can be 



Studies in Infantile Paralysis 59 

drawn from our own series on this point, while not of any great 
weight, is, as far as it goes, directly contradictory to this 
theory. Infantile diarrheas of the more severe forms are very 
prevalent in the eastern section of the state, while no por- 
tions of the United States are so free from these disorders as 
the coastal regions of the states of Washington and Oregon. 
Nevertheless, infantile paralysis was, in proportion to the popu- 
lation, slightly more prevalent in the western section of the 
state than in the eastern section during the present outbreak. 

Attention has already been drawn to the fact that in a very 
high percentage of this series constipation and not diarrhea 
was the noticeable feature, both previous to and during the 
acute onset. 

Variations in temperature and amount of rainfall have also 
been advanced as possible factors in the transmission of infantile 
paralysis. The effect of these two factors is extremely prob- 
lematical, although in some respects the peculiarities of tem- 
perature and rainfall in this state furnish very suggestive data 
from w^hich interesting deductions might be drawn. 

However, there are certain factors in regard to infantile 
paralysis which promptly prohibit theorizing upon these very 
interesting fields of speculation ; for example, the manner in 
which the disease breaks out in very isolated communities will 
call for a great deal of careful investigating before the travel 
theory can be given too serious weight. The manner in which 
the disease will attack the largest and best paved and mx)st 
thoroughly sprinkled cities, as in the case of this state, while 
at the same time it entirely passes by smaller but still consider- 
able sized communities, where there is very little if any paving 
and where the dust is ten times more prevalent, imposes grave 
difficulties in the acceptance of the dust theory. 

RELATION OF TEMPERATURE AND RAINFALL. 

The relationship between the prevalence of infantile paralysis 
and deficiency of rainfall has been very frequently observed. 
The state of Washington, in many respects, furnishes an un- 
usual opportunity for the observations of the effect of climate 



60 Washington State Board of Health 

upon disease, since there are not only the major divisions be- 
tween the two sides of the state, with their radically different 
climates, but each one of these divisions is still further sub- 
divided into very distinct belts in regard to rainfall, and, to a 
lesser degree, temperature conditions. 

Quoting from the report of the section director of the 
Weather Bureau, we learn that the year 1910, as a whole, was 
of normal mean temperature ; that the sumrrier months all over 
the state were cool; that all the weather observation stations 
in the eastern portion of the state showed temperatures of over 
90 degrees, and a great majority of them in July and August 
showed maximum temperatures of approximately 100 degrees, 
while few of the stations on the western side of the state showed 
temperatures of 90 degrees at any time. The year's precipita- 
tion as a whole was not greatly below normal, but during the 
spring and summer there was almost unprecedented dryness. 

In the note under August it was stated that August was the 
sixth consecutive month with a deficient precipitation over the 
state as a whole. This is the sam'e month in which the greatest 
number of cases of infantile paralysis were reported. 

In many communities it is very interesting to note how the 
disease very abruptly ceased with the oncoming of the heavy 
fall rains. This data is not in any sense conclusive evidence 
that deficient precipitation of rain has a direct bearing upon 
the prevalence of infantile paralysis, but it is very interesting 
to note that this disease should for the first tirhe have become 
seriously prevalent in this state during a summer of remark- 
able deficiency in rainfall. Yet even within our own state there 
is very striking climatological evidence which would apparently 
prevent the conclusions that the prevalence of the disease is 
very directly affected by the absence of rainfall. There is one 
belt extending on an average for 150 miles north and south 
and over one hundred miles in width along the Columbia river 
in which the total rainfallfor the year is always less than 12 
inches, and nearly all the total precipitation for the year is 
in the four months of November, December, Januarv and Feb- 



Studies in Infantile Paralysis 61 

ruary ; and in all parts of the eastern half of the state the 
rainfall rarely exceeds 15 or 20 inches per year; whereas over 
the western portion of the state the rainfall is always 30 inches 
or more ; yet infantile paralysis was slightly more prevalent in 
the western division. On the other hand, it is important to 
remember, as above stated, that just at the time when the out- 
break was at its height that the climatic conditions of the 
Sound, on account of the unusual deficiency in rainfall, more 
nearly approximated the usual conditions of the Inland Empire 
than had been the case for many years. 



APPKNDIX 



REPORT UPON OCCURENCE OF INFANTILE PARAL- 
YSIS IN THE CITY OF SEATTLE DURING 

THE SEASON OF 1910 



By DR. WILLIS H. HALL 
Medical Inspector of the Seattle Department of Health 



INTRODUCTORY NOTE. 

The cases reported in this section do not entirely correspond 
with the number of cases given for Seattle in the general re- 
port, because the total number of cases in the other portion of 
the report represent the 88 cases analyzed here, together with 
20 others which were reported to the State Board of Health 
and not to the city of Seattle. 



The first appearance of infantile paralysis in epidemic form 
in Seattle was ushered in somewhat suddenly, the first reported 
case being August 6, 1910; the next two follow on August 9th. 
The total number of cases in the city as reported to the de- 
partment of health and listed as such comprise a total of eighty- 
eight cases. 

The number of cases occurring from August to the end of 

1910 by months is as follows: 

Total number of cases reported during the month of August.... 32 

Total number of cases reported during the month of September. 32 

Total number of cases reported during the month of October.... 15 

Total number of cases reported during the month of November.. 9 

Total number of cases reported during the month of December. .None 

A few of the cases reported in August were sick in July, 
thus cutting down the actual number of infections in August 
below the apparent number as given above, and making the 
mon th of September the one in which the greater number of 
cases were reported. 

These cases were gone over carefulh^ by the department, and 
reports from the attending physician, and from the quarantine 
officer were used as a soiu'cc of information in tabulating cases. 



66 Washington State Board of Health 



It will be noticed that there were 15 cases in the month of 
October, and that the month following there were but 9 cases. 
The commencement of the rainy season may possibly have had 
some influence in causing the decrease. 

As to the sex of the 88 cases, 54 were males and 34 females, 
and no case of infection occurred in any but the white race. 
In a town whose population is so heterogeneous, this may be 
considered as of some importance along the line of race sus- 
ceptibility. 

The segregation by ages shows that the greatest susceptibility 

is previous to and during the third year, after which time the 

susceptibility to the disease seems to diminish, yet no age is 

entirely exempt. 

In persons aged 1 year or under 12 cases 

In persons aged 2 years or under 13 cases 

In persons aged 3 years or under 12 cases 

In persons aged 4 years or under 9 cases 

In persons aged 5 years or under 11 cases 

In persons aged 6 years or under 8 cases 

In persons aged 7 years or under 2 cases 

In persons aged 8 years or under 3 cases 

In persons aged 9 years or under 1 case 

In persons aged 10 years or under 2 cases 

In persons aged 11 to 15 years 6 cases 

In persons aged 15 to 20 years 4 cases 

In persons aged 36 to 46 years 2 cases 

The two cases occurring between thirty-six and forty-six 
are secondary infections from other cases in the same house. 

The reports on sanitary conditions are more or less a matter 
of judgment and it is sometimes hard to draw an exact line in 
the classification of conditions as found around private dwell- 
ings. Of the seventy cases reported on but one was bad, 17 
were fair, and 52 were good. 

Of sixty-eight cases, the detached house predominated, being 
fifty-two in number, while thirteen cases occurred in apartment 
houses, fifty-eight houses w^ere situated high and dry and only 
three where it was low and damp. Forty-nine houses were thor- 
oughly screened and thirty-seven without screens. Either dogs 
or cats were kept in twenty houses. City water was used in 
most of the houses, being piped to seventy-two, and spring water 
was used by three. Milk was used or obtained from public 



Studies in Infantile Paralysis 67 



dairies by forty-eight, private dairies, thirty-one, and nine used 
condensed milk. The private dairy includes those who got 
milk from neighbors and those who got milk from their own 
cows. This shows that in the preponderance of cases the san- 
itary conditions could not well be held responsible for the pres- 
ence of the contagion, but the sanitary conditions can influ- 
ence the progress and the ultimate result after infection has 
already taken place. Also as to toilet accessories, the modern 
flush toilet was used in sixty-six houses and only twenty-one 
were using outside vaults or cesspools. 

The symptoms of the period of onset may be said to be of 
considerable importance, as a correct interpretation of symp- 
toms leads to a correct diagnosis, still the request for the 
symptoms of onset were largely ignored, and the tabulated re- 
plies gives the following result : 

Fever well marked 1 case 

Vomiting 6 cases 

Constipation 10 cases 

Sore throat 7 cases 

Retraction of head 1 case 

Pain (distribution not given) 1 case 

Tenderness (distrubtion not given)..... 1 case 

These are all classical symptoms and throw no new light on 
the symptomatology of the disease. 

One of the important things seems to me to be the fact that in 
regard to the streets which these house were situated upon, 
fourteen were paved and forty-four on streets not paved. Prac- 
tically all the paved streets are washed, and the unpaved streets 
are not, showing the part which dust might play in the prev- 
alence and distribution of the disease. 

As to the distribution of epidemic infantile paralysis in Seattle, 
the configuration of the city of Seattle is peculiar, having a 
narrow portion between Elliot Bay and Lake Washington, 
widening out to the north and also to the south, the cit}^ being 
narrowest about Yesler Way. This street roughly divides the 
city into two parts or halves as to area, but the south half is 
thinly settled, not containing any congested portion of the pop- 
ulation. Very little of the district south of Yesler Way is paved 
and a very large part not yet graded. In looking over the distri- 



68 Washington State Board of Health 

bution of cases of infantile paralysis in the south half of town, 
there are eight cases along the Rainier Valley, which is a valley 
beginning south of Yesler Wa}^ and running in a general di- 
rection south and east for about seven miles from the con- 
gested portion of town. Until very recently there has been 
no attempt to grade streets in this district. The main travel 
goes up and down the one street. The cross streets, on ac- 
count of the country being hilly, are very seldom traveled and 
very often a street has nothing but a foot path or a board 
sidewalk, and no wagon road at all. Under these circum- 
stances, it may be readily seen that dust would not be as prev- 
alent as in a paved district. Also in this district the houses 
are farther apart and the virus or contagion would necessarily 
have to travel farther to pass from one house to another. 

In the district of West Seattle a similar condition exists, in 
that few streets are graded, none paved, large areas being un- 
settled but containing a population of approximately 30,000 
people, and in this district we find eleven cases, while the re- 
maining sixty-nine cases occurred in the north half of town, 
or on the other side of Yesler Way. There were no cases in 
what is called the Fort Lawton district, extending from Smith's 
Cove north and west to Fort Lawton, and embracing that dis- 
trict south of Salmon Bay to Elliot Bay. This district is also 
very sparsely settled, large areas not being built upon. In the 
more congested portion of the residence district which lies be- 
tween Elliot Bay on the west and Lake Washington on the 
east, but between Denny Way and Yesler Way, there occurred 
the most of the fatal cases. Queen Anne hill with the portion 
of Capital hill and the district lying north of Denny Way 
contained twenty-five cases, this district being most all paved 
and graded. In the district north of the canal, including what 
used to be the town of Ballard, Fremont, and University dis- 
tricts, where the streets are most all graded, but with a small 
amount of paving laid, and the population not congested, there 
Occurred twenty-five cases. It seems to me that these two dis- 
tricts both together having fifty cases out of the total of eighty- 



Studies in Infantile Paralysis 



nine, with no congestion of population, show the exact effect of 
•dust in the carrying of the contagion or that the conditions ex- 
isting which favor the carrying of dust also favor the trans- 
mission of this contagion. Outside of the congested portion of 
town lying between Yesler Way and Denny Way, there is very 
little of the streets that are sprinkled, most of the sprinkled 
territory lying in the business district. 

Conclusions. 

The smaller number of cases after the commencement of the 
rainy season may be due to one or all of the following causes : 

(a.) Lower temperature produced by rain. 

(b.) Less dust in the air on account of rain. 

(c.) Lessened mingling with other children on account of 
damper weather. 



LeAp'i2 



